1. Field of the Invention
The present invention relates to a keyboard device for use in a keyboard instrument such as a piano, and a keyboard instrument including the keyboard device.
2. Description of the Related Art
For example, a keyboard device such as a piano is known which includes a wippen that rotates by a key depression operation, a jack that is driven in response to the rotating motion of the wippen, and a hammer member that is driven by the jack and strikes a string such that these components are provided corresponding to a plurality of keys, as described in Japanese Patent Application Laid-Open (Kokai) Publication No. 2002-258835.
This type of keyboard device is structured such that, when a key is depressed, the wippen is rotated by the depressed key, and the jack incorporated in this wippen is driven by the wippen to press up the hammer member, whereby the hammer member is rotated and strikes the string.
However, in this keyboard device, not only a repetition lever for incorporating the jack in the wippen but also a support rod for supporting this repetition lever on the wippen is required. Therefore, there is a problem in that the number of the components is increased and the structure is complicated. Moreover, in order to acquire an optimum key-touch feel, the weight of the hammer member is required to be adjusted, which makes the structure further complicated.
This key-touch feel is determined by the state of counterforce applied to a key after key depression. FIG. 13 is a graph showing the state of counterforce in a general acoustic piano. The horizontal axis represents elapsed time after key depression, and the vertical axis represents the magnitude of counterforce.
The key-touch feel significantly varies particularly depending on timing when counterforce reaches its peak after key depression (in FIG. 13, time t=b).
Because this timing when the counterforce reaches its peak is determined by various elements regarding the wippen and the hammer member such as their positional relation, structure, weight, and materials, it cannot be adjusted easily.